client/src/app/core/rest/rest.service.ts

   1 import { SortMeta } from 'primeng/api'
   2 import { HttpParams } from '@angular/common/http'
   3 import { Injectable } from '@angular/core'
   4 import { ComponentPaginationLight } from './component-pagination.model'
   5 import { RestPagination } from './rest-pagination'
   6
   7 interface QueryStringFilterPrefixes {
   8   [key: string]: {
   9     prefix: string
  10     handler?: (v: string) => string | number
  11     multiple?: boolean
  12     isBoolean?: boolean
  13   }
  14 }
  15
  16 type ParseQueryStringFilters <K extends keyof any> = Partial<Record<K, string | number | boolean | (string | number | boolean)[]>>
  17 type ParseQueryStringFiltersResult <K extends keyof any> = ParseQueryStringFilters<K> & { search?: string }
  18
  19 @Injectable()
  20 export class RestService {
  21
  22   addRestGetParams (params: HttpParams, pagination?: RestPagination, sort?: SortMeta | string) {
  23     let newParams = params
  24
  25     if (pagination !== undefined) {
  26       newParams = newParams.set('start', pagination.start.toString())
  27                            .set('count', pagination.count.toString())
  28     }
  29
  30     if (sort !== undefined) {
  31       let sortString = ''
  32
  33       if (typeof sort === 'string') {
  34         sortString = sort
  35       } else {
  36         const sortPrefix = sort.order === 1 ? '' : '-'
  37         sortString = sortPrefix + sort.field
  38       }
  39
  40       newParams = newParams.set('sort', sortString)
  41     }
  42
  43     return newParams
  44   }
  45
  46   addArrayParams (params: HttpParams, name: string, values: (string | number)[]) {
  47     for (const v of values) {
  48       params = params.append(name, v)
  49     }
  50
  51     return params
  52   }
  53
  54   addObjectParams (params: HttpParams, object: { [ name: string ]: any }) {
  55     for (const name of Object.keys(object)) {
  56       const value = object[name]
  57       if (value === undefined || value === null) continue
  58
  59       if (Array.isArray(value)) {
  60         params = this.addArrayParams(params, name, value)
  61       } else {
  62         params = params.append(name, value)
  63       }
  64     }
  65
  66     return params
  67   }
  68
  69   componentToRestPagination (componentPagination: ComponentPaginationLight): RestPagination {
  70     const start: number = (componentPagination.currentPage - 1) * componentPagination.itemsPerPage
  71     const count: number = componentPagination.itemsPerPage
  72
  73     return { start, count }
  74   }
  75
  76   /*
  77   * Returns an object containing the filters and the remaining search
  78   */
  79   parseQueryStringFilter <T extends QueryStringFilterPrefixes> (q: string, prefixes: T): ParseQueryStringFiltersResult<keyof T> {
  80     if (!q) return {}
  81
  82     // Tokenize the strings using spaces that are not in quotes
  83     const tokens = q.match(/(?:[^\s"]+|"[^"]*")+/g)
  84                     .filter(token => !!token)
  85
  86     // Build prefix array
  87     const prefixeStrings = Object.values(prefixes)
  88                            .map(p => p.prefix)
  89
  90     // Search is the querystring minus defined filters
  91     const searchTokens = tokens.filter(t => {
  92       return prefixeStrings.every(prefixString => t.startsWith(prefixString) === false)
  93     })
  94
  95     const additionalFilters: ParseQueryStringFilters<keyof T> = {}
  96
  97     for (const prefixKey of Object.keys(prefixes) as (keyof T)[]) {
  98       const prefixObj = prefixes[prefixKey]
  99       const prefix = prefixObj.prefix
 100
 101       const matchedTokens = tokens.filter(t => t.startsWith(prefix))
 102                                   .map(t => t.slice(prefix.length)) // Keep the value filter
 103                                   .map(t => t.replace(/^"|"$/g, '')) // Remove ""
 104                                   .map(t => {
 105                                     if (prefixObj.handler) return prefixObj.handler(t)
 106
 107                                     if (prefixObj.isBoolean) {
 108                                       if (t === 'true') return true
 109                                       if (t === 'false') return false
 110
 111                                       return undefined
 112                                     }
 113
 114                                     return t
 115                                   })
 116                                   .filter(t => t !== null && t !== undefined)
 117
 118       if (matchedTokens.length === 0) continue
 119
 120       additionalFilters[prefixKey] = prefixObj.multiple === true
 121         ? matchedTokens
 122         : matchedTokens[0]
 123     }
 124
 125     return {
 126       search: searchTokens.join(' ') || undefined,
 127
 128       ...additionalFilters
 129     }
 130   }
 131 }